Can Cats Eat Tuna?

Cats love to eat tuna. When you open a can of tuna, it doesn’t take long for your cat to be attracted to the enticing scent. You want your cat to enjoy its favorite food, but you are unsure if tuna is suitable for cats.

Cats should not be given tuna on a daily basis as it can cause mercury poisoning. Just 85 grams of tuna contains 10.71 mcg of mercury. While tuna is rich in protein, omega-3 fatty acids, and B vitamins, it lacks many nutrients that cats need to stay healthy. Cats should not be given canned tuna, tuna in oil, or tuna in brine.

Tuna can be addictive to cats because of its rich texture and intense flavor.

There is no harm in occasionally giving your cat tuna in spring water, but it is recommended to use high-quality tuna-based cat food.

Why Do Cats Like Tuna So Much?

It may be that some cats have no interest in tuna. But that tends to be the exception to the rule. So why do cats like tuna?

  • Tuna has a strong, fishy smell that is very attractive to cats.
  • It has a unique taste that is different from white-fleshed fish.
  • It is rich in proteins.
  • Tuna often comes in brine or sunflower oil, which cats love to ingest.

Unfortunately, the best-tasting food is not always the healthiest for cats.

Is Tuna Bad for Cats?

Tuna is perfectly fine for cats in moderation. However, too much of it can be unhealthy.

The reasons why tuna is unhealthy for cats include:

  • Sodium: Canned tuna in brine contains a lot of sodium, which is salt. This can lead to dehydration, high blood pressure, and urinary problems.
  • Phosphorus: It is unsuitable for cats with kidney disease.
  • Thiaminase: Some types of tuna contain the enzyme thiaminase, which destroys thiamine (vitamin B1). This can lead to a vitamin B1 deficiency.
  • Low taurine: Cats need to get taurine from their diet.
  • Mercury: Canned tuna contains mercury, which is toxic not only to cats.
  • Steatitis: It occurs when a cat does not receive vitamin E. This can lead to inflammation of fat cells and tissues.

Is Tuna Good for Cats?

If cats only get tuna occasionally, it has a few benefits. Here’s how healthy tuna can be for cats:

  • Smell: Tuna can stimulate a cat’s appetite when it eats reluctantly.
  • Lysine: Tuna is rich in the amino acid lysine, essential for cats.
  • Docosahexaenoic acid (DHA): DHA supports your cat’s brain and eye health.
  • Protein: In the wild, a cat’s diet is rich in protein. Cats need protein-rich foods for muscle development and growth.
  • Energy: It is known that consuming omega-3 fatty acids, vitamin B complex, and thiamine gives the cat more power.
  • Blood circulation: Riboflavin, niacin, iron, and potassium improve the cat’s blood circulation and the multiplication of red blood cells. This can be useful if your cat has circulatory problems.

What is the Best Type of Tuna for Cats?

Some types of tuna are better for cats than others. Here are the healthiest ways to feed tuna to your cat:

Canned Or Cooked Tuna

Although raw has some health benefits, you should not feed raw tuna to cats. Raw tuna contains thiaminase, an enzyme that destroys thiamine, or vitamin B1.

The canning and cooking process destroys thiaminase, so canned or cooked tuna is less likely to cause vitamin B1 deficiency than raw tuna.

Tuna in Spring Water

If you feed your cat canned tuna, ensure it is in spring water. Your cat shouldn’t eat tuna in sunflower oil or brine.

The sodium in brine can lead to dehydration, and overconsumption of sunflower or olive oil can cause diarrhea.

Other types of fish are also best in spring water. Cats also like sardines, and there, too, the variety in spring water is considered best.

Low-Mercury Tuna

All fish and shellfish contain some mercury due to water pollution.

Large and long-lived fish, such as bluefin tuna or albacore, contain higher levels of mercury than smaller fish.

Farmed tuna contains less mercury than wild-caught fish.

So you can buy a product with lower mercury levels but choose tuna in chunks. This is made from smaller tuna such as skipjack and tongol tuna.

These fish live in shallower waters and have eaten fewer prey during their lifetime. As a result, the mercury concentration in their bodies is much lower.

Tuna-Based Cat Food

If you are concerned about the health risks of canned tuna, we recommend buying tuna-flavored cat food.

Canned tuna does not count as a balanced meal because it contains little taurine.

You should choose a complete, nutritionally balanced cat food with tuna on the ingredient list instead.

How to Get the Benefits of Tuna for Your Cat

The safest way to feed your cat tuna is to provide a complete cat food containing tuna.

This way, your cat benefits from the high docosahexaenoic acid (DHA) content in tuna and still gets a nutritionally balanced meal.

In addition, tuna-flavored cat food still smells and tastes like tuna. It is, therefore, ideal for cats who like tuna or those with a low appetite.

Thanks to technological advances, the most valuable ingredient in tuna, docosahexaenoic acid, can now be found in other foods.

How to Feed Canned Tuna to Your Cat

Tuna-based cat food is the safest way to feed your cat tuna. However, that doesn’t mean you should never feed your cat canned tuna.

An occasional serving of canned tuna is unlikely to harm your cat as long as you keep the following in mind:

Tuna is Not a Meal Replacement

Canned tuna does not replace a cat’s meal because it has no balanced nutritional value.

It is okay to give your cat a few pieces of canned tuna. But this should be in addition to their regular meals.

Do Not Encourage Tuna Addiction

You may, of course, treat your cat to tasty foods like tuna.

However, make sure that you also give her alternative treats. This should keep your cat from becoming obsessed with tuna.

Try feeding your cat special cat treats or spoiling her in other ways.

For example, you can pet or play with your cat when it tries to manipulate you to get extra food.

Use Tuna to Lure Your Cat

If your cat is a reluctant eater and you want to stimulate her appetite with tuna, chop up a few pieces of light tuna and sprinkle it over her food.

Canned tuna can be very useful in helping stressed or older cats regain their appetite.

Give Tuna Only in Moderation

Give your cat canned tuna no more than once a week, and keep portions small.

Tuna is Not Suitable for All Cats

If your cat has a chronic health problem such as kidney disease, you should not give him canned tuna.

However, it is unlikely that an occasional serving would cause health problems.

Is My Cat Overeating Tuna?

It can be easy to overfeed our cats or give them too many treats. It’s difficult to tell a cat no when begging for their beloved fish-based food.

But how can you tell that your cat is overeating tuna? These symptoms caused by a diet high in tuna are:

  • Problems with urine
  • Lethargy
  • Decreased vocalization
  • Increased appetite
  • Weight loss
  • Excessive water consumption
  • Slow-healing wounds due to vitamin E deficiency

Other factors besides excessive consumption of canned tuna could also cause these symptoms, so there are no definite signs of overeating canned tuna.

However, if you suspect feeding your cat too much tuna, you should reduce the amount.

When Should Cats Not Eat Tuna?

Because of the risks, there are situations when cats should never be fed tuna.

Kidney Problems

Cats with kidney disease benefit from high-quality, digestible protein. However, canned tuna is unsuitable in such a situation because it contains high phosphorus levels.

A diet high in phosphorus accelerates the development of kidney disease.

Cat food for kidney disease patients often contains rabbit meat, which is naturally low in phosphorus.

Heart Disease

A cat with a heart condition is fed a diet low in sodium and high in taurine. However, canned tuna contains a lot of sodium and little taurine and is therefore unsuitable.


Salted tuna is not suitable for cats with diabetes because it causes dehydration.

Fish Allergies

Symptoms of tuna allergy include intense scratching, bloating, hyperactivity, and vomiting.

Allergies are difficult to diagnose when a cat eats a variety of foods.

If you have noticed digestive problems in your cat, it is possible that an occasional piece of tuna is to blame.

If you suspect a food allergy, you should eliminate one food at a time to determine which is the cause.

Mercury Poisoning

The risks of fish and mercury poisoning are well-known. But does cat food contain so much mercury that cat owners should be concerned about mercury poisoning from fish-based cat food?

In one study, researchers examined the mercury content of 101 pet foods and found the following:

  • Mercury was present in all samples.
  • 14 of the 101 samples had unusually high mercury levels compared to the rest.
  • Foods containing tuna and shrimp had the highest mercury concentrations.
  • Samples from different batches of the same cat food had different levels of mercury.

However, veterinarians very rarely detect mercury poisoning in cats.

But that doesn’t mean minor, gradual damage isn’t caused by moderate amounts of mercury in cat food.

When Cats Become Addicted to Tuna

Cats can develop an unhealthy addiction to tuna over time. Some cats become incredibly picky about food and refuse to eat anything but tuna.

Addicted cats may even become aggressive if they don’t get their tuna.

Here’s how to deal with a cat that is addicted to tuna:

Use Other Cat Food

Introduce cat food with other flavors. Rabbit has a relatively strong flavor and is low in phosphorus, making it a healthy alternative to tuna for cats.

Avoid Tuna As a Treat

If you give your cat small pieces of tuna as treats, try to replace them with other tasty food. You could try tuna-flavored treats, a bit of cooked chicken, or another intense flavor.